The most popular pipe coupling presently used for the above purposes is of the type known as hingeable split collar. It comprises a matched pair of half-circular collars hinged to each other at one end and provided with lugs at the other end. The collars are formed with rims or shoulders adapted to fit into and hold against complementary circumferential grooves formed near the ends of the pipes. An elastomeric circular gasket is used, surrounding the space between and partly extending over the pipe ends. Once the collars are tightened to each other, by a bolt passing through the respective lugs overlying each other, the gasket becomes compressed to provide a seal between the pipes.
Pressure admitted into the pipes is effective to enhance the sealing effect by further pressurizing of the gasket against the rims of the collars.
These split collar couplings are inherently inconvenient for use, demanding certain manipulation and application of physical force during the initial mounting stage.
Other deficiencies of the conventional couplings are that they need to be made of metal, and hence they are heavy and wasteful in terms of storage and transportation space.
It is the prime object of the present invention to provide a pipe coupling of simple, plastic molded integral construction, and allowing a wide range of variations satisfying different pipe-work conditions.
It is a further object of the invention to make use of the standard grooved pipe ends as applied in conjunction with the split collar couplings.